1. Field of the Invention
The present invention is directed to methods of playing games of chance and gaming systems for conducting shared bonus events in a manner to weight the odds among participating gaming entities according to qualifying activities associated with playing a base or primary game.
2. State of the Art
Games of chance have been enjoyed by people for thousands of years and have enjoyed widespread popularity in recent times. Many people enjoy playing variations of games that they have not previously played before. Playing new variations of games adds to the excitement of this recreational activity particularly when some form of gaming is involved. As used herein, the terms “gaming” and “gaming devices” are used to indicate that some form of wagering is involved and that players must make wagers of value, whether actual currency or some equivalent of value, e.g., token or credit.
Players involved in games of wagering often enjoy new games or variations of old games with relatively simple rules that can be readily learned by a beginner or casual player. Variations to a game with respect to the method of wagering and the ability to increase winnings attract more players and are highly desired in the industry. The ability to increase winnings where risk is involved based on the selection of a possible random outcome is also highly desired. There has been an evolution of gaming devices over the past few decades. At the beginning of this evolution stand-alone, mechanical and electromechanical gaming devices, such as the traditional slot machine, dominated the industry. The advent of relatively inexpensive computer processors and associated video display devices supported by sophisticated hardware and software to drive same has allowed the introduction of computer-emulated games and a simulated display of the game sequence and outcome. The next evolutionary step was the integration of communication capabilities between computers and gaming devices, allowing the interchange of data between computers using a communication link in the form of a network.
The development of communications capability between gaming machines and between gaming machines and a host computer over a network permitted the development of systems allowing the players at linked gaming machines to compete for additional prizes while playing traditional wagering games. Exemplary of these systems are conventional progressive gaming systems, such as those disclosed in U.S. Pat. No. 4,837,728 and U.S. Pat. No. 5,855,515, the disclosures of each of which patents are incorporated herein by reference. In a progressive system, a number of gaming machines are linked together, an additional or bonus game is made available responsive to a preselected outcome, and in many instances a threshold wager is made, in the base or primary game on the gaming machine. The potential bonus prize increases in value as wagers are placed on the linked gaming machines and a portion of each wager is diverted to the progressive prize pool until a progressive win is triggered at one of the participating gaming machines.
One progressive gaming system of note is disclosed in U.S. Pat. No. 5,645,486, the disclosure of which is incorporated herein by reference. In this system, a number of gaming machines are linked together and a progressive bonus prize is accumulated and available to players. To qualify for the progressive bonus prize, a player must obtain (for example) in play of a video poker game with a maximum wager of five coins, a combination of symbols on the screen of a gaming machine representing a royal flush hand of poker cards. When a player obtains the royal flush but has not placed the maximum wager of five coins, that player obtains an opportunity to be awarded the progressive bonus prize through a lottery. The odds of winning the lottery are related to the number of coins wagered less than the maximum. Should an “entry” to the lottery held by the player be randomly selected in lottery play, the progressive bonus is awarded. As with other progressive systems, each coin drop freezes the amount of the possible bonus payable for that game. When a player wins the lottery, the available amount of the progressive bonus is awarded and the progressive game restarts. While players are attracted to play when larger progressive bonuses accumulate, after an award of a significant bonus interest in playing the linked gaming machines can wane. Further, as each coin drop represents a chance to acquire the progressive bonus, no advantage is obtained by a player by continuing play or by obtaining certain results during play toward achieving the progressive bonus payout.
A current enhancement to the market is the addition of secondary or bonus games (as opposed to bonus prizes associated with play of a game in which lesser prizes may be won) to gaming machines offering play of a base or primary game. These gaming machines allow a player achieving a preselected outcome during play of a base or primary game to participate in an additional or “bonus” game and thereby have a chance to earn an additional payout or bonus prize. The bonus game is typically a single event or a sequential event where progress through the bonus game is determined by the continuation of play on the slot machine. Examples of such bonus games are disclosed in U.S. Pat. No. 6,089,978, U.S. Pat. No. 6,089,976 and U.S. Pat. No. 5,796,716, the disclosures of each of which are incorporated herein by reference. These bonus games begin when a selected random event occurs in a primary game on a gaming machine. The bonus game is then activated and begins. At the end of the game, an indicated payout value is awarded as a bonus. The games disclosed in the aforementioned patents respectively employ a prize wheel that spins, a number of computer generated options that are selected to receive bonuses until an end game signal is reached, or a dexterity or skill based video game. The starting point and ending point of each bonus game determines the value of the bonus prizes that may be awarded. The odds of winning each bonus of the randomly determined outcome bonus games remain the same for each occurrence of the game.
U.S. Pat. No. 6,159,097 discloses a gaming machine offering a basic game and a bonus game. In one embodiment, the probability of winning certain ones of a plurality of bonus payouts varies in response to different basic game outcomes which initiate the bonus game. In another embodiment, the bonus game includes a number of player-selectable elements, at least one of which represents a winning bonus game outcome. The value of the bonus payout successively decreases as the number of non-winning elements selected by the player increases before a winning element is selected.
U.S. Pat. No. 5,129,652, the disclosure of which is incorporated herein by reference, discloses a method of using a drawing to encourage customers to visit a casino or a related casino. Upon entering the casino, a customer fills out a card. A drawing of cards is held to award prizes to customers in the casino. A portion of the card is retained and allows for discounts on services or other additional inducements. Eligibility for drawings is maintained by staying at the casino or visiting a related casino and additional prizes become available to those who return to a participating casino within a certain time span. This method requires a player to spend additional time filling out forms, checking results and visiting alternative casinos to improve their odds. Casual players may choose not to participate to save the time and effort involved and the distraction caused by drawings unrelated to the current activity of a player may reduce the amount of time that player spends gaming.
The networking of computers has also allowed and improved the ability to track the usage of individual gaming machines including the players using such a machine. Player tracking systems allow for the management of large numbers of gaming machines and players simultaneously. Examples of player tracking systems may be found in U.S. Pat. No. 6,165,071, U.S. Pat. No. 6,048,269, and U.S. Pat. No. 5,655,961, the disclosures of each of which are incorporated herein by reference. These systems allow players to carry credits from one gaming machine to another, thereby avoiding the use of coins or tokens, to track the gaming usage of the players for marketing purposes, and to allow the players to play for a higher payout upon meeting certain conditions. U.S. Pat. No. 6,165,071 discloses the use of player tracking to allow gaming to transpire over a series of sessions without a player losing credit for performances in earlier sessions.
It would be desirable to encourage players to continue their play on a gaming machine by providing prizes that are available through a shared bonus event. It would be particularly desirable to weight each player's odds of winning a shared bonus event prize in a manner proportionate to the player's time spent playing a base or primary game, wagers made during play thereof, success at playing a base or primary game, or other activity associated with play of a base or primary game through which one qualifies to enter or participate in the shared bonus event. It may be further desirable for such a system to allow a player to retain any unused entries for a shared bonus event remaining at the end of a period of play of a primary or base game and use those entries in a later session of play or to allow a player to be awarded a shared bonus event prize after ending play and then claim the prize in a later session of play, thus encouraging players to return later.